The invention is directed to application of electromagnetically actuated devices and more particularly a method and system of selectively utilizing a set of linear actuator motors for an application. Merely by way of example, the invention has been applied to techniques related to reduce tooling investment with flexible assembly means for meeting customer's equipments. But it would be recognized that the invention has a much broader range of applicability.
Rotary stepping motors are widely known and used in various technical fields. One of the common form of such a stepping motor has a toothed motor and a stator with poles constructed appropriately for certain number of steps. Stepping motors that operate in steps are commonly used in connection with digital equipment wherein pulses are applied to the stepping motor which is used as an actuator.
Linear electromagnetic actuators are also known in the art, such devices embodying linearly movable armature members having teeth which are associated with a stator having poles and windings which are energizable to cause the movable member to move in the direction of its length. Linear actuator motors combine the rotary stepping motor and the linear actuator so that the linearly movable armature member is driven by a toothed rotor coupled with the stator. An example of such linear actuator includes a lead screw interlocked by a nut disposed at certain location of a shaft.
Linear actuator motors are widely used in fields from consumer electronics products to medical instruments or custom laboratory equipments. Particularly, for medical applications and custom experimental applications, devices combining rotary and linear positioning mechanisms need to provide flexibility in terms of both functional characters and structural characters. For example, for certain application, it requires a system that offers a set of different linear actuator motors each offering different power ratings in terms of the value of torques provided. Correspondingly it is desirable to make the system flexible in terms of selectively utilizing the set of linear actuator motors economically.
However, the prior arts are lacking to meet the specific requirements mentioned above and beyond in terms of the particular constructional improvements of the invention described in detail hereinafter. For example, the nut for interlocking the linear actuator is usually built inside the motor assembly not easily accessible by customer. The nature of the improvements is brought out more clearly in the detailed description hereinafter of the preferred embodiment.